Bilayer-passivated stable dif-TES-ADT organic thin-film transistors.

The active region of organic thin film transistors (OTFTs) is usually sensitive to moisture and O₂ in the air ambient, which hinders their practical applications. In this study, the effects of air ambient on characteristics of unpassivated 2,8-difluoro-5,11-bis (triethylsilylethynyl) anthradithiophene (dif-TES-ADT) OTFTs are clarified. The device is much more sensitive to H₂O vapor than O₂, although both of which cause TFT instability. To improve the environmental stability, inkjet-printed passivation of the fluoropolymer CYTOP and UV curing adhesive are compared. It is found that the CYTOP passivation is well compatible with the organic channel while the UV curing adhesive has excellent barrier ability to both H₂O vapor and O₂. Then CYTOP/UV adhesive bilayer passivation combining advantages of both materials is introduced to achieve stable operation of OTFTs, which can resist saturated H₂O vapor and O₂ for 25 days. [ABSTRACT FROM AUTHOR]